As detailed in a McKinsey survey , most US corporations have an executive chairman of the board of directors; typically, the CEO serves as chairperson. The US is relatively unique among major economies in this regard; in most, companies generally separate the CEO and board chair roles by law or practice.
Nonexecutive board chairs (and/or so-called lead independent directors) have been one of the major corporate governance "reform" proposals in recent years. Curiously, however, I can't find much evidence that separating the two roles improves corporate performance and/or has a positive stock price effect. Holmstrom and Kaplan's major survey of the corporate governance literature, for example, cites but a single study, which looked at the impact of various UK corporate governance rules on CEO turnover. The study found that the beneficial results "appear to have been driven by the increase in the fraction of outsiders on the board rather than the separation of the chairperson and CEO."
All of this is called to mind by the HP Leakgate. HP became one of the leading US companies to separate the CEO and chair roles after the board fired Carly Fiorina. Reportedly, however, if current board chairwoman Patricia Dunn steps down, CEO Mark Hurd may "emerge as chairman." Will it matter? In the absence of compelling evidence, count me as a skeptic. My intuition is that this sort of thing is mostly window dressing.
